Protein A chromatography is routinely employed as a first capture step in industrial monoclonal antibody purification processes due to its high selectivity, resulting in good overall yields and purities. However, a major drawback of this affinity chromatography is its high price, which especially in case of therapeutic antibodies needed at high doses and/or for chronic administration can account for a significant cost of goods factor. In addition, leached protein A ligand from the affinity matrix must be removed by further chromatography steps due to its potential immunogenicity.
Mixed mode chromatography on multimodal resins exhibiting ionic and hydrophobic functionalities can offer a valuable alternative to the classical affinity approach. Due to the salt tolerability of the hydrophobic component, in most cases a direct loading of the clarified cell culture supernatant on the matrix is possible resulting in an effective capturing the monoclonal antibody. However, due to the multimodal nature of the resin, different types of interaction of the ligand with a particular monoclonal antibody are possible, requiring unique wash and elution condition differing from traditional ion-exchange or hydrophobic interaction chromatography.
In WO 2010/080062 a separation method using single polymer phase systems is reported. A manufacturing process for the production of polypeptides expressed in insect cell lines is reported in WO 2008/073620.